High efficiency of self-assembly between exfoliated MXene and layered-double-hydroxide nanosheets in exploring high-performance oxygen evolution reaction electrocatalysts

High-performance oxygen electrocatalysts have attracted tremendous research attention because of their crucial roles in diverse renewable energy technologies such as metal-oxygen batteries, fuel cells, and water electrolyzers. In this study, a novel lattice manipulation strategy for the exploration of highly active electrocatalysts was established via self-assembly between exfoliated MXene and layered double hydroxide (LDH) nanosheets (NSs). Electrostatically-driven self-assembly between cationic Co-Fe-LDH and anionic MXene NSs yielded intimately-coupled Co-Fe-LDH-MXene nanohybrids with porous stacking structures and significant interfacial charge transfer. The self-assembled Co-Fe-LDH-MXene nanohybrid delivered excellent electrocatalyst functionality with a lowered overpotential of 252 mV at 10 mA cm⁻² that is much better than those of the precursor Co-Fe-LDH and MXene NSs. The outstanding electrocatalytic activity of the self-assembled Co-Fe-LDH-MXene nanohybrid highlights a high efficacy of the self-assembly methodology in exploring high-performance electrocatalysts. In situ surface enhanced Raman scattering analysis during electrocatalysis found that the enhanced redox activity of metal cations achieved by intimate electronic coupling with ultrathin conductive MXene NSs mainly contributes to the improved performance of the Co-Fe-LDH-MXene nanohybrids for oxygen evolution reaction.